Swain 1981

Methods	Randomised controlled trial with three groups.
Participants	Country: USA. Setting: PHC. Health problem: hypertension. Recruitment: health system. Participants: adults (n=115).
Interventions	Contract features: Form: written; Parties: patients‐carers; Incentives: other; Co‐interventions: yes. Group 1: Education booklet plus contingency contracts with behavioural goals; patients received an agreed reward from a nurse for reaching agreed goals. Group 2: Education booklet. Group 3: Usual care only.
Outcomes	Change in knowledge score, number of participants discontinuing treatment, diastolic blood pressure.
Notes
Risk of bias
Item	Authors' judgement	Description
Allocation concealment?	Unclear	B ‐ Unclear